<template>
  <div id="app">
    <!-- - 需求1: 铺设页面, 准备初始的数据(自己手写数据结构) - 前面是数组索引+1 *作为序号
         - 需求2: 当输入框没有值, 要给用户一个提示, 必须都有值才能增加新数据 (数据驱动页面哦)
         - 需求3: 添加功能 - 想好数据结构统一对象的key
         - 需求4: 点击编辑功能, 把值赋予到输入框上(不要操作dom, 数据驱动页面)
         - 需求5: 用户修改后, 点击相同按钮 - 想想怎么判断怎么是添加还是修改的功能 (提示: 准备一个全局变量, 点过编辑按钮可以让它为true) - 实现编辑后更新页面效果
         - 需求6: 点击删除, 删除这行数据
 -->
    <div>
      <span>姓名:</span>
      <input type="text" v-model="newArr.name" />
    </div>
    <div>
      <span>年龄:</span>
      <input type="number" v-model="newArr.age" />
    </div>
    <div>
      <span>性别:</span>
      <select v-model="newArr.sex">
        <option value="男">男</option>
        <option value="女">女</option>
      </select>
    </div>
    <div>
      <button @click="add" :value="flag">添加/修改</button>
    </div>
    <div>
      <table border="1" cellpadding="10" cellspacing="0">
        <tr>
          <th>序号</th>
          <th>姓名</th>
          <th>年龄</th>
          <th>性别</th>
          <th>操作</th>
        </tr>
        <tr v-for="(item, index) in arr" :key="index">
          <td>{{ index + 1 }}</td>
          <td>{{ item.name }}</td>
          <td>{{ item.age }}</td>
          <td>{{ item.sex }}</td>
          <td>
            <button @click="del(index)">删除</button>
            <button @click="edit(index)">编辑</button>
          </td>
        </tr>
      </table>
    </div>
  </div>
</template>

<script>
export default {
  data() {
    return {
      flag: true,
      arr: [
        { id: 0, name: "张冬凯", age: 20, sex: "男" },
        { id: 1, name: "张三", age: 21, sex: "男" },
        { id: 2, name: "李四", age: 22, sex: "男" },
      ],
      // name: "",
      // age: "",
      // sex: "",
      newArr: { id: "", name: "", age: "", sex: "" },
    }
  },
  methods: {
    del(id) {
      this.arr = this.arr.filter((item, index) => index !== id)
    },
    edit(id) {
      this.flag = false
      this.newArr = { ...this.arr[id] }
    },

    add() {
      if (this.name === "" && this.age === "" && this.sex === "") {
        return alert("数据不能为空")
      }
      if (this.flag) {
        this.arr.push({
          id: this.arr.length,
          name: this.newArr.name,
          age: this.newArr.age,
          sex: this.newArr.sex,
        })
        this.newArr.name = this.newArr.age = this.newArr.sex = ""
      } else {
        this.open = true // 增加按钮
        if (this.newArr.name === "" || this.newArr.sex === "")
          return alert("输入不能为空")

        this.arr.forEach((item) => {
          if (item.id === this.newArr.id) {
            this.arr.splice(this.newArr.id, 1, {
              id: this.newArr.id,
              name: this.newArr.name,
              age: this.newArr.age,
              sex: this.newArr.sex,
            })
          }
        })
      }
    },
  },
}
</script>

<style></style>
